试图让鱼朝着它的方向移动

Question

到目前为止，我正在制作一个应用程序，它的早期阶段只是一条鱼在一个小盒子周围游动。我制作了随机改变鱼类方向的代码，如果它达到某些x或y值，则使其保持在相机的可见度范围内。不幸的是我的C＃知识是有限的，我无法弄清楚如何让它改变它的方向，这是我的代码

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class FishBehavior : MonoBehaviour {

    public float speed = 2f;
    float moveSpeed = 0f;
    private Rigidbody2D rigid;
    public float rotateSpeed = 2f;
    public bool isPredator = false;

    void Start () {
        rigid = GetComponent<Rigidbody2D>();
        rigid.velocity = new Vector2(speed, 0);
        InvokeRepeating("FishMovement", 3f, Random.Range(2f,6f));

    }

    // Update is called once per frame
    void Update () {
        int num = Random.Range(1, 10);
        if (transform.position.x >= 11.5)
        {
            speed = -2;
            rigid.velocity = new Vector2(speed, 0);
        }
        if (transform.position.x <= -11.5)
        {
            speed = 2;
            rigid.velocity = new Vector2(speed, 0);
        }
        if (transform.position.y >= 5.07)
        {
            rigid.velocity = new Vector2(Random.Range(-2, 2), -2);

        }
        if (transform.position.y <= -4.65)
        {
            rigid.velocity = new Vector2(Random.Range(-2, 2), 2);
        }
    }
    void FishMovement()
    {
        int fishSpeed = Random.Range(-3, 3);
        if (fishSpeed != 0)
        {
            moveSpeed = Random.Range(-2, 2);
            rigid.velocity = new Vector2(fishSpeed, moveSpeed);
        }
    }
}

任何事情都有帮助谢谢